Inpaichthys luizae - Black Arrow Tetra

Common Name: Black Arrow Tetra, Luiza's Tetra
Scientific Name: Inpaichthys luizae
Native Region: Mato Grosso, Brazil
Origin: Tank Bred, USA
Adult Size: Approximately 1.25–1.5"
Temperament: Peaceful
Diet: Omnivore / Micropredator
Currently Feeding On: EBO Sealife Proaktiv, EBO Artemia Softgran, EBO Insect Softgran
Swimming Level: Mid to upper water column
Recommended Group: 8+

The Black Arrow Tetra (Inpaichthys luizae) is a spectacular and exceptionally rare South American tetra that was formally described in 2025. Native to tributaries of the Rio dos Peixes in the Rio Juruena basin of Mato Grosso, Brazil, this species is one of the newest additions to the aquarium hobby.

What immediately sets I. luizae apart is its bold, oblique dark stripe running diagonally along the body and continuing onto the middle rays of the caudal fin. This dramatic marking is contrasted by a bright orange stripe above it, while the body develops olive-green and blue iridescence with purplish coloration, particularly in males. The fins are yellow to orange, giving this tetra an exceptional combination of dark, metallic, and warm colors.

Males are typically smaller and more intensely colored than females, with particularly strong coloration in the unpaired fins and along the dark lateral stripe. Like other members of Inpaichthys, they are peaceful schooling fish and are best appreciated when kept in a proper group. Their small size and striking appearance make them an excellent choice for planted community aquariums.

In nature, I. luizae is currently known from freshwater tributaries in the Rio dos Peixes drainage. The known habitats are reported to be relatively well preserved, making this a particularly exciting species for aquarists interested in unusual and newly described Brazilian fishes.

Care Requirements

Temperature: 74–80°F
pH: 5.5–7.0
Tank Size: 20 gallons or larger
Water: Soft to moderately soft
Group Size: 8 or more

Black Arrow Tetras are omnivores and should be offered a varied diet of quality flakes and appropriately sized micro pellets. Regular additions of frozen or live foods such as daphnia, cyclops, baby brine shrimp, and other small aquatic foods will help maintain condition and bring out their best coloration.

A planted aquarium with driftwood, subdued lighting, and areas of cover is an excellent setup for this species. Darker substrates can also provide a beautiful contrast against their orange fins and distinctive dark lateral stripe.

Their peaceful temperament makes them well suited to community aquariums with other similarly sized, non-aggressive fish. Small tetras, pencilfish, Corydoras, and other peaceful South American species make excellent companions. Avoid large or boisterous tankmates that may outcompete them for food or cause unnecessary stress.

Difficulty: Easy to Moderate
Breeding: Egg scatterer; males and females show noticeable sexual dimorphism, and breeding can be encouraged with soft, clean water and appropriate spawning media.

Why We Like Them

• Exceptionally rare and newly described species

• Striking black arrow-shaped lateral stripe

• Brilliant orange and yellow fins

• Beautiful blue, green, and purple iridescence

• Peaceful schooling behavior

• Excellent choice for planted South American aquariums

• One of the newest Inpaichthys species available to the hobby

All livestock is carefully quarantined and monitored before being offered for sale at Saburai Aquatics.